Reinforced refractory crucibles for melting titanium alloys

ABSTRACT

Reinforced crucibles for melting titanium alloys having a facecoat including at least one facecoat layer, a backing including at least one backing layer, and at least one reinforcing element applied to at least a portion of one or more of the facecoat layer, the backing layer, or a combination thereof where the reinforcing element includes at least one composition selected from ceramic compositions, metallic compositions, and combinations thereof.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application claims priority to U.S. Provisional Application Ser.No. 60/914,935, filed Apr. 30, 2007, which is herein incorporated byreference in its entirety.

TECHNICAL FIELD

Embodiments described herein generally relate to reinforced cruciblessuitable for melting titanium alloys. More particularly, embodimentsherein generally describe reinforced refractory crucibles suitable formelting highly reactive titanium alloys, such as titanium aluminide.

BACKGROUND OF THE INVENTION

Turbine engine designers are continuously looking for new materials withimproved properties for reducing engine weight and obtaining higherengine operating temperatures. Titanium alloys, and in particular,titanium aluminide (TiAl) based alloys, possess a promising combinationof low-temperature mechanical properties, such as room temperatureductility and toughness, as well as high intermediate temperaturestrength and creep resistance. For these reasons, TiAl-based alloys havethe potential to replace nickel-based superalloys, which are currentlyused to make numerous turbine engine components.

Vacuum induction melting is one method often used to make turbine enginecomponents, such as airfoils, and generally involves heating a metal ina crucible made from a non-conductive refractory alloy oxide until thecharge of metal within the crucible is melted down to liquid form. Whenmelting highly reactive metals such as titanium or titanium alloys,vacuum induction melting using cold wall or graphite crucibles istypically employed. This is because melting and casting from ceramiccrucibles can introduce significant thermal stress on the crucible,which can result in the crucible cracking. Such cracking can reducecrucible life and cause inclusions in the component being cast.

Moreover, difficulties can arise when melting highly reactive alloys,such as TiAl, due to the reactivity of the elements in the alloy at thetemperatures needed for melting to occur. As previously mentioned, whilemost vacuum induction melting systems use refractory alloy oxides forcrucibles in the induction furnace, alloys such as TiAl are so highlyreactive that they can attack the refractory alloys present in thecrucible and contaminate the titanium alloy. For example, ceramiccrucibles are typically avoided because the highly reactive TiAl alloyscan break down the crucible and contaminate the titanium alloy with bothoxygen and the refractory alloy from the oxide. Similarly, if graphitecrucibles are employed, the titanium aluminide can dissolve largequantities of carbon from the crucible into the titanium alloy, therebyresulting in contamination. Such contamination results in the loss ofmechanical properties of the titanium alloy.

Additionally, while cold crucible melting can offer metallurgicaladvantages for the processing of the highly reactive alloys describedpreviously, it also has a number of technical and economic limitationsincluding low superheat, yield losses due to skull formation and highpower requirements. These limitations can restrict commercial viability.

Accordingly, there remains a need for reinforced crucibles for use inmelting highly reactive alloys that are more resistant to thermalstresses generated during the casting process and less likely tocontaminate the alloy.

BRIEF DESCRIPTION OF THE INVENTION

Embodiments herein generally relate to reinforced crucibles for meltingtitanium alloys comprising a facecoat including at least one facecoatlayer; a backing including at least one backing layer; and at least onereinforcing element applied to at least a portion of one or more of thefacecoat layer, the backing layer, or a combination thereof wherein thereinforcing element comprises at least one composition selected from thegroup consisting of ceramic compositions, metallic compositions, andcombinations thereof.

Embodiments herein also generally relate to reinforced crucible formelting titanium alloys comprising a facecoat including at least onefacecoat layer; a backing including at least one backing layer; a stuccolayer applied to at least one of the facecoat layer or the backinglayer; and at least one reinforcing element applied to at least aportion of any one or more of the facecoat layer, the backing layer, thestucco layer, or a combination thereof wherein the reinforcing elementcomprises a configuration selected from the group consisting of acontinuous fiber, a tape, a mesh, a chopped fiber, and combinationsthereof.

Embodiments herein also generally relate to reinforced crucible formelting titanium alloys comprising at least a base region; a transitionregion; a lower region; and a plurality of reinforcing elementconfigurations selected from the group consisting of a continuous fiber,a tape, a mesh, a chopped fiber, and combinations thereof wherein a meshreinforcing element configuration is positioned about at least a portionof the base region and the transition region, and a continuous fiberreinforcing element configuration is positioned about at least a portionof the lower region.

These and other features, aspects and advantages will become evident tothose skilled in the art from the following disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the invention, it is believed that theembodiments set forth herein will be better understood from thefollowing description in conjunction with the accompanying figures, inwhich like reference numerals identify like elements.

FIG. 1 is a schematic perspective view of one embodiment of a cruciblein accordance with the description herein;

FIG. 2 is a schematic perspective view of one embodiment of a form inaccordance with the description herein;

FIG. 3 is a schematic cross-sectional view of one embodiment of acrucible mold in accordance with the description herein;

FIG. 4 is a schematic close-up view of a portion of a cross-section ofthe crucible mold of FIG. 3;

FIG. 5 is an elevated front view of one embodiment of a crucible moldwith reinforcing elements positioned in an adjacent orientation inaccordance with the description herein;

FIG. 6 is an elevated front view of one embodiment of a crucible moldwith two reinforcing elements, each applied to a different layer of thecrucible mold, in accordance with the description herein;

FIG. 7 is an elevated front view of one embodiment of a crucible moldwith reinforcing elements positioned in a stacked orientation inaccordance with the description herein; and

FIG. 8 is a schematic cross-sectional view of one embodiment of acrucible mold after the form has been removed and a topcoat applied inaccordance with the description herein.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments described herein generally relate to refractory cruciblessuitable for melting titanium alloys. More specifically, embodimentsdescribed herein generally relate to reinforced refractory crucibles formelting titanium alloys comprising a facecoat including at least onefacecoat layer, a backing including at least one backing layer, and atleast one reinforcing element applied to at least a portion of one ormore of the facecoat layer, the backing layer, or a combination thereofwherein the reinforcing element comprises at least one compositionselected from the group consisting of ceramic compositions, metalliccompositions, and combinations thereof.

While embodiments herein will generally focus on reinforced cruciblessuitable for melting TiAl for use in making near net shape airfoils, thedescription should not be limited to such. Those skilled in the art willunderstand that the present embodiments may be suitable for melting anytitanium alloy for use in making any near net shape gas turbinecomponent.

Turning to FIG. 1, embodiments herein relate to a refractory crucible 8suitable for melting titanium alloys. Crucible 8 can have an interior 9and can be made in accordance with the description herein below. Tobegin, a crucible mold can be made. As used herein “mold” refers to theunfired components that when fired under suitable conditions formcrucible 8 of FIG. 1. To make a crucible mold, a form 10 can beprovided, as shown in FIG. 2. While form 10 can comprise any materialcapable of removal from the crucible mold, in one embodiment, form 10can comprise wax, plastic or wood, and may be hollow or solid. Moreover,form 10 can take any shape and have any dimension necessary to producethe desired interior of the crucible and may comprise a handle 12, orother like mechanism, for ease of handling.

As shown in FIGS. 3 and 4, a facecoat 16 comprising at least onefacecoat layer 18, and optionally at least one stucco layer 20, can beapplied to form 10. As used herein throughout, “at least one” means thatthere may be one or more than one and specific layers will be designatedherein throughout as “first facecoat layer,” “second facecoat layer,”and the like. Since facecoat layer 18 can be exposed to the TiAl duringthe melting process, facecoat layer 18 should be inert to the reactiveTiAl so as not to degrade and contaminate the alloy during melting.Therefore, in one embodiment, face coat layer 18 may comprise an oxide.As used herein throughout, “oxide” refers to a composition selected fromthe group consisting of scandium oxide, yttrium oxide, hafnium oxide, alanthanide series oxide, and combinations thereof. Furthermore, thelanthanide series oxide (also known as “rare earth” compositions) maycomprise an oxide selected from the group consisting of lanthanum oxide,cerium oxide, praseodymium oxide, neodymium oxide, promethium oxide,samarium oxide, europium oxide, gadolinium oxide, terbium oxide,dysprosium oxide holmium oxide, erbium oxide, ytterbium oxide, lutetiumoxide, and combinations thereof.

Facecoat layer 18 may comprise a facecoat slurry made from a powder ofthe oxide mixed into a colloidal suspension. In one embodiment, theoxide powder may be a small particle powder having a size of less thanabout 70 microns, and in another embodiment, from about 0.001 microns toabout 50 microns, and in yet another embodiment from about 1 micron toabout 50 microns. The colloid can be any colloid that gels in acontrolled fashion and is inert to TiAl, such as, for example, colloidalsilica, colloidal yttria, colloidal alumina, colloidal calcium oxide,colloidal magnesium oxide, colloidal zirconium dioxide, colloidallanthanide series oxides, and mixtures thereof. While any of thepreviously listed oxides can be used to make the facecoat slurry offacecoat layer 18, in one embodiment, the facecoat slurry may compriseyttrium oxide particles in a colloidal silica suspension, while inanother embodiment, the facecoat slurry may comprise yttrium oxideparticles in a colloidal yttria suspension. The composition of thefacecoat slurry can vary, however, in general, the facecoat slurry maycomprise from about 40% to about 100% of the oxide and from about 0% toabout 60% of the colloid, by weight.

Once the facecoat slurry of facecoat layer 18 is prepared usingconventional practices, form 10 may be exposed to the facecoat slurryusing a method selected from the group consisting of dipping, spraying,and combinations thereof. Generally, once applied, facecoat layer 18 canhave a thickness of from about 50 microns to about 500 microns, and inone embodiment from about 150 microns to about 300 microns, and in yetanother embodiment about 200 microns.

While still wet, facecoat layer 18 may optionally be coated with astucco layer 20, as shown in FIGS. 3 and 4. As used herein, “stucco”refers to coarse ceramic particles generally having a size greater thanabout 100 microns, and in one embodiment from about 100 microns to about5000 microns. Stucco 20 can be applied to each facecoat layer to helpbuild up the thickness of the crucible wall and provide additionalstrength. A variety of materials may be suitable for use as stucco layer20, however, in one embodiment, the stucco may comprise a refractorymaterial, such as, but not limited to, alumina or aluminosilicates,combined with an oxide, as defined herein. The ratio of the refractorymaterial to the oxide in stucco layer 20 can vary, however, in oneembodiment, stucco layer 20 can comprise from about 0% to about 60% ofthe refractory material and from about 40% to about 100% of the oxide,by weight. Stucco layer 20 may be applied to facecoat layer 18 in anyacceptable manner, such as dusting for example. Generally, stucco layer20 can have a thickness of from about 100 microns to about 2000 microns,and in one embodiment from about 150 microns to about 300 microns, andin yet another embodiment about 200 microns.

Facecoat layer 18, and optional stucco layer 20 can be air-dried andadditional facecoat layers and stucco layers may be applied in themanner described previously, if desired, to complete facecoat 16. In theembodiments shown in FIGS. 3 and 4, first and second facecoat layers 18,and alternating stucco layers 20, are present, though those skilled inthe art will understand that facecoat 16 may comprise any number offacecoat layers and stucco layers. While each facecoat layer 18 maycomprise a different oxide/colloid mixture, in one embodiment, eachfacecoat layer 18 comprises the same oxide/colloid mixture. Once thedesired number of facecoat layers 18 and stucco layers 20 have beenapplied, a backing 22 may then be applied.

Backing 22 can help provide additional strength and durability to thefinished crucible 8. As such, backing 22 may consist of at least onebacking layer 24, shown in FIG. 4, which can comprise a backing slurryincluding a refractory material selected from the group consisting ofaluminum oxide, zirconium silicate, silicon dioxide, and combinationsthereof, in a colloidal silica suspension. Specific layers may bedesignated herein throughout as “first backing layer,” “second backinglayer,” and the like. As an example, in one embodiment, backing layer 24may comprise a backing slurry made from aluminum oxide particles in acolloidal silica suspension. The composition of the backing slurry canvary, however, in general, the backing slurry may comprise from about10% to about 40% of the refractory material and from about 60% to about90% of the colloid, both by weight. Similar to the facecoat layers, eachbacking layer 24 may optionally comprise a stucco layer 20 adheredthereto, as shown in FIG. 4, which may be the same as or different fromthe stucco used previously to make the facecoat. Each backing layer 24,including the stucco, can have a thickness of from about 150 microns toabout 4000 microns, and in one embodiment from about 150 microns toabout 1500 microns, and in yet another embodiment about 700 microns.

Similar to the facecoat layers, each backing layer 24 may be appliedusing a method selected from the group consisting of dipping, spraying,and combinations thereof. While any number of backing layers 24 can beapplied, in one embodiment, there may be from 2 to 40 backing layers.Each backing layer 24 may comprise the same composition of refractorymaterial and colloid, each may be different, or they may comprise somecombination in between. After applying the desired number of backinglayers, and optional stucco layers, the resulting crucible mold 26 canbe further processed.

It should be noted that in some cases it may be desirable to grade thestucco layers by altering particle size, layer thickness and/orcomposition as they are applied. As used herein, the term “grade,” andall forms thereof, refers to gradually increasing the strength ofsubsequently applied stucco layers by, for example, increasing theparticle size of the stucco material, increasing the thickness of thestucco layer and/or utilizing increasingly stronger refractorymaterial/colloid compositions as the stucco layer. Such grading canallow the stucco layers to be tailored to account for differences inthermal expansion and chemical properties of the various facecoat layersand backing layers to which they are applied. More specifically, gradingthe stucco layers provides differing porosities and can adjust themodulus of the crucible, which taken together, can help account for thedifferences in thermal expansion as previously discussed.

At any time during the construction of the crucible mold, at least onereinforcing element 14 may be applied to at least a portion of any oneor more of facecoat layer 18, backing layer 24, or a stucco layer 20thereof. In the embodiments of FIGS. 3, 4, 5 and 8, reinforcing element14 is shown applied to a stucco layer 20 of facecoat 16. However, thoseskilled in the art will understand that this embodiment is forillustration purposes only and should not be used to limit the scope ofthe present description.

Reinforcing element may comprise anything capable of increasing thestrength of the finished crucible and its resistance to thermal crackingin comparison to crucibles lacking such reinforcing elements. As usedherein, “reinforcing element” refers to compositions applied to one ormore layers of the crucible mold during construction, rather than tooxides, refractory materials and/or colloids present in the layers ofthe crucible mold that may react to form reinforcing materials duringthe firing the of the crucible mold, as explained herein.

While reinforcing element 14 may be made from any number ofcompositions, in one embodiment, reinforcing element 14 may comprise acomposition selected from the group consisting of ceramic compositions,metallic compositions and combinations thereof. More specifically,reinforcing element 14 may comprise at least one ceramic compositionselected from the group consisting of yttria, alumina, sapphire,nitride, yttrium aluminum garnet (YAG), silicon carbide (SiC), siliconaluminum oxinitride (such as SiAlON™), silica, mullite (such asNEXTEL™), zirconia, zircon, zircar, and combinations thereof; at leastone metallic composition selected from the group consisting of tungsten,tantalum, molybdenum, niobium, rhenium, alloys thereof, and combinationsthereof. Additionally, reinforcing element 14 may comprise a combinationof ceramic compositions and metallic compositions, known as cermets,which can include, but should not be limited to, alumina-50% molybdenum,alumina-90% molybdenum, alumina-50% tungsten, and alumina-90% tungsten,by volume.

Reinforcing element 14 may comprise any configuration capable ofproviding increased strength and resistance to thermal cracking to thefinished crucible. In one embodiment, reinforcing element 14 maycomprise a configuration selected from the group consisting of acontinuous fiber, tape, mesh, chopped fiber, and combinations thereof.The dimensions of the configuration may vary, such as by width,thickness, weave, and the like, according to characteristics desired inthe reinforcing element. However, in one embodiment, reinforcing elementcan have a thickness of less than about 2000 microns, and in anotherembodiment from about 100 microns to about 1000 microns.

Additionally, a single configuration may be applied, or more than oneconfiguration may be applied, to the same layer, or different layers, ofthe crucible mold. If more than one reinforcing element is applied tothe same layer, the reinforcing elements may be applied in an adjacentorientation, a stacked orientation, or some combination thereof, asdescribed herein below. For instance, in one embodiment shown in FIG. 5,both a continuous fiber element and a mesh element may be applied to thesame layer in an adjacent orientation. In another embodiment shown inFIG. 6, a mesh element and chopped fiber elements may be applied todifferent layers. In yet another embodiment shown in FIG. 7, a tapeelement and chopped fiber elements may be applied to the same layer in astacked orientation.

Moreover, reinforcing element 14, the composition thereof, and theconfiguration thereof, may be selected to support particular stressespresent in different regions of the crucible, such as the base region30, the transition region 32 (i.e. the portion connecting base region 30to lower region 34), the lower region 34 (i.e. the sides containing thetitanium melt during casting), the upper region 36 (i.e. the sides abovethe titanium melt during casting) 34, and the pour lip region 38, asindicated generally in FIG. 5. In particular, as bending stresses may besignificant in base 30, transition 32, and pour lip 36 regions, it maybe desirable to utilize at least a mesh reinforcing element 14 in theseregions, as shown in FIG. 5. Similarly, in the sides of the crucible(i.e. the upper 36 and lower 34 regions), hoop stresses will generallybe the principal concern and thus, it may be desirable to utilize atleast a continuous fiber reinforcing element 14 in such regions, asshown in FIG. 5. By specifically tailoring the reinforcing element tothe particular regions of the crucible, thermal stress resistance can beoptimized to help ensure the crucible maintains its integrity throughoutthe heating, melting, pouring, and cool-down phases.

Regardless of the composition or configuration of reinforcing element14, the application thereof generally follows the same procedure. The atleast one reinforcing element 14 may be applied about the selectedlayer, or layers, while the slurry is still wet. Applying reinforcingelement 14 while the selected layer is still wet allows reinforcingelement 14 to become secured to crucible mold 26. More particularly, asthe selected layer of crucible mold 26 dries, reinforcing element 14 canadhere thereto. The application of reinforcing element 14 can include,but should not be limited to, wrapping or winding reinforcing element 14about the selected layer(s) of crucible mold 26, as shown in FIGS. 5 and7, or in the case of chopped fibers, pressing or dusting reinforcingelement 14 in the desired location or locations about the selected layerof crucible mold 26, as shown in FIGS. 6 and 7. If more than onereinforcing element is used, and a stacked orientation is selected (seeFIG. 7 for example), the previously described techniques can be employedto apply one reinforcing element over another. Those skilled in the artwill understand that the reinforcing elements can be either selectivelyplaced about at least a portion of a selected layer of the cruciblemold, or alternately, about and entire selected layer of the cruciblemold.

Crucible mold 26 may then be dried using conventional practices and form10 may be removed. A variety of methods may be used to remove form 10from crucible mold 26. As previously mentioned, form 10 may comprise waxand therefore may be removed by placing crucible mold 26 in a furnace,steam autoclave, microwave, or other like device, and melting form 10leaving an open interior 9 in crucible mold 26, as shown in FIG. 8. Thetemperature required to melt form 10 from crucible mold 26 can generallybe low and in one embodiment, can range from about 40° C. to about 120°C.

Optionally, interior 9 of crucible mold 26 may then be washed with acolloidal slurry to form a topcoat 28, as shown in FIG. 8. Washing cangenerally involve applying a coating to the interior of the crucibleusing any method known to those skilled in the art, such as spraying,prior to firing the crucible. Topcoat 28 can have any desired thickness,however, in one embodiment, topcoat 28 has a thickness of up to about500 microns, and in another embodiment from about 20 microns to about400 microns. Topcoat 28 can comprise a colloidal slurry selected fromthe group consisting of yttria in a colloidal yttria suspension, yttriain a colloidal silica suspension, and combinations thereof. This topcoatcan help further ensure that the crucible will remain inert with respectto the titanium alloy during melting.

The hollow crucible mold 26 can then be fired to higher temperatures.Firing crucible mold 26 can help provide additional strength to thefinished crucible because during this heating process, the materialsthat make up the facecoat layers, stucco, and backing layers caninterdiffuse with one another and sinter together. Initially, thecrucible mold can be fired to a temperature of from about 800° C. toabout 1400° C., and in one embodiment from about 900° C. to about 1100°C., and in one embodiment about 1000° C. This first firing can takeplace for any length of time needed to help burn off any remaining formmaterial, as well as provide a limited degree of interdiffusion amongthe ceramic constituents of the crucible, which in one embodiment may befrom about 0.5 hours to about 50 hours, in another embodiment from about1 hour to about 30 hours, and in yet another embodiment about 2 hours.Next, the crucible mold can be fired to a temperature of from about1400° C. to about 1800° C., and in one embodiment from about 1500° C. toabout 1800° C., and in yet another embodiment from about 1600° C. toabout 1700° C. This second firing can take place for any length of timeneeded to substantially complete the interdiffusion of the ceramicconstituents, as well as cause a reaction of the colloid present in thefacecoat oxide, which in one embodiment may be from about 0.5 hours toabout 50 hours, in another embodiment from about 1 hour to about 30hours, and in yet another embodiment about 2 hours. For example,colloidal silica can form silicates, while colloidal yttria can sinterwith yttria particles present in the slurry of the facecoat.

Once firing is complete, the resulting crucible can be suitable for usein melting titanium alloys. While specific characteristics of crucible 8can be altered or modified depending on the desired use, in oneembodiment, crucible 8 can have an overall wall thickness, that includesall facecoat layers, stucco layers and backing layers, of at least about3 mm, and in another embodiment at least about 6 mm, and in yet anotherembodiment from about 6.5 mm to about 40 mm. Wall thicknesses of greaterthan about 40 mm can lead to undesirably long high heating times.Similarly, the thickness ratio of the backing to the facecoat can, inone embodiment, be from about 6.5:1 to about 20:1. As above, thicknessratios greater than about 20:1 can result in undesirably long highheating times due to the thickness of the alumina backing layers.

Regardless of the specific construction, crucible 8 may be used to melttitanium alloys having a low interstitial level and a low ceramicinclusion content. In particular, TiAl can be melted in the crucibledescribed herein using conventional melting and casting techniques knownto those skilled in the art. The crucibles described herein are capableof use with such highly reactive alloys because the materials used tomake the facecoat are inert to the reactive TiAl. In other words, thefacecoat can be exposed to the TiAl during melting without degrading andcontaminating the alloy. Moreover, the crucibles herein can be heatedrapidly without cracking during any of the melting, pouring, casting andcooling stages of the vacuum induction melting cycle.

The net result of this improved crucible performance is that thecrucible is more resistant to thermal stresses and the TiAl meltedtherein remains more pure and has improved fatigue life. As used herein,“pure” means that the alloy has an oxygen content of less than about1200 ppm by weight, and includes less than about 500 ppm by weight ofyttrium or silicon contaminates generated by the crucible during themelting process. Due to this improved purity, components made from theTiAl exhibit less cracking and fewer imperfections than those made fromTiAl using current methods.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to make and use the invention. The patentable scope of the inventionis defined by the claims, and may include other examples that occur tothose skilled in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral language of the claims.

1. A reinforced crucible for melting titanium alloys comprising: afacecoat including at least one facecoat layer; a backing including atleast one backing layer; and at least one reinforcing element applied toat least a portion of one or more of the facecoat layer, the backinglayer, or a combination thereof wherein the reinforcing elementcomprises at least one composition selected from the group consisting ofceramic compositions, metallic compositions, and combinations thereof.2. The crucible of claim 1 wherein the reinforcing element comprises atleast one ceramic composition selected from the group consisting ofyttria, alumina, sapphire, yttrium aluminum garnet, silicon carbide,silicon aluminum oxinitride, mullite, zirconia, zircon, zircar, andcombinations thereof.
 3. The crucible of claim 1 wherein the reinforcingelement comprises at least one metallic composition selected from thegroup consisting of tungsten, tantalum, molybdenum, niobium, rhenium,alloys thereof, and combinations thereof.
 4. The crucible of claim 1comprising a stucco layer applied to at least at portion of any of thefacecoat layer, the backing layer, or a combination thereof.
 5. Thecrucible of claim 1 wherein the reinforcing element comprises aconfiguration selected from the group consisting of a continuous fiber,a tape, a mesh, a chopped fiber, and combinations thereof.
 6. Thecrucible of claim 1 wherein the at least one reinforcing element isapplied to the entire facecoat layer, backing layer, stucco layer, orcombination thereof.
 7. The crucible of claim 5 wherein more than onereinforcing element configuration is applied in a manner selected fromthe group consisting of an adjacent orientation, a stacked orientation,or a combination thereof.
 8. The crucible of claim 4 wherein more thanone of the facecoat layer, the backing layer, and the stucco layercomprises a reinforcing element.
 9. The crucible of claim 5 wherein thecrucible further comprises any of a base region, a transition region, alower region, an upper region and a pour lip region.
 10. The crucible ofclaim 9 wherein the reinforcing element application is tailored tosupport particular stresses present in different regions of thecrucible.
 11. The crucible of claim 9 comprising a mesh reinforcingelement configuration positioned about at least a portion of the baseregion and the transition region, and a continuous fiber reinforcingelement configuration positioned about at least a portion of the lowerregion.
 12. The crucible of claim 1 further comprising a topcoatincluding a yttrium oxide powder in a colloidal suspension wherein thecolloidal suspension comprises a colloid selected from the groupconsisting of colloidal silica, colloidal yttria, and combinationsthereof.
 13. A reinforced crucible for melting titanium alloyscomprising: a facecoat including at least one facecoat layer; a backingincluding at least one backing layer; a stucco layer applied to at leastone of the facecoat layer or the backing layer; and at least onereinforcing element applied to at least a portion of any one or more ofthe facecoat layer, the backing layer, the stucco layer, or acombination thereof wherein the reinforcing element comprises aconfiguration selected from the group consisting of a continuous fiber,a tape, a mesh, a chopped fiber, and combinations thereof.
 14. Thecrucible of claim 13 wherein the reinforcing element comprises at leastone composition selected from the group consisting of ceramiccompositions, metallic compositions, and combinations thereof.
 15. Thecrucible of claim 13 wherein the at least one reinforcing element isapplied to the entire facecoat layer, backing layer, stucco layer, orcombination thereof.
 16. The crucible of claim 13 wherein more than onereinforcing element configuration is applied in a manner selected fromthe group consisting of an adjacent orientation, a stacked orientation,or a combination thereof.
 17. The crucible of claim 13 wherein more thanone of the facecoat layer, the backing layer, and the stucco layercomprises a reinforcing element.
 18. The crucible of claim 13 whereinthe crucible comprises at least two different regions and thereinforcing element application is tailored to support particularstresses present in the different regions of the crucible.
 19. Areinforced crucible for melting titanium alloys comprising at least: abase region; a transition region; a lower region; and a plurality ofreinforcing element configurations selected from the group consisting ofa continuous fiber, a tape, a mesh, a chopped fiber, and combinationsthereof wherein a mesh reinforcing element configuration is positionedabout at least a portion of the base region and the transition region,and a continuous fiber reinforcing element configuration is positionedabout at least a portion of the lower region.